Vacuum web-drier



. Patented Oct. 25, I898. H. PARKER &. H. FAIRBANKS. VACUUM WEB DRIER.

' (Application filed Feb. 10, 1897.) (No Model.) 3 Sheets-Sheet I.

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Patented Oct. 25, I898.

H. PARKER & H. FAIRBANKS.

VACUUM WEB DRIER.

(Application filed Feb. m 1897.)

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(No Model.)

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I-IOlVARD PARKER AND HENRY FAIRBANKS, OF ST. J OI-INSBURY, VERMONT,

ASSIGNORS TO THE VACUUM DRIER COMPANY, OF VERMONT.

VACUUM WEB-DRIER.

SPECIFICATION forming part of Letters Patent No. 612,931, dated October25, 1898.

Application filed February 10, 1897. Serial No. 622,'768. (No model.)

To all whom it may concern:

Be it known that we, HOWARD PARKER and HENRY FAIRBANKS, 'of St.Johnsbury, in the county of Caledonia and State of Vermont, haveinvented a new and useful Vacuum WVeb- Drier for Paper, Oloth, and Yarn,of which the following, taken in connection with the accompanyingdrawings, is a specification.

Our invention is a machine for rapidly drying yarn, warps, cloth in theweb, or paper as it runs from the paper-machine or wet-machine; and itconsists of a chamber partly exhausted of air through which this yarnweb or sheet is drawn in contact with heated surfaces, with suitabledevices for guiding it through as well as for maintaining the vacuum.

It is usual to provide a paper-machine with stacks of steam-heated rolls(twenty or more being required for a quick-running web) to evaporate thewater against the pressure of the atmosphere without heating it so muchas to seriously injure the fiber, and cloth and warps require similarprovision. We find that by removing part of the atmospheric pressure welower the temperature of the boiling-point of water so much that thedegree of heat which will not injure the fabric is sufficient to driveoff all the water with a short exposure, and the web runs out of theexhausted chamber perfectly dry. In order to maintain the vacuum, it isnecessary to have air-tight packings for all the moving parts whichproject from the inside of the closed chamber and to provide for drawingin and carrying out the web to be treated between elastic rolls, whichwill close over it and not allow a stream of air to pass in with it. Thethin air left in the vacuum-chamber is so poor a conductor of heat thatthe web can hardly be sufficiently heated to drive off its moistureexcept by being in contact with the heated surfaces, and We use one ormore cylinders heated from within and so propelled that the web movesforward in contact with them, they and the elastic rolls at the entranceand exit being geared together in a way to insure equal surface travelfor all, and to make sure that the web shall keep its course as providedfor it we run two series of metallic tapes, or in some cases two clothor wire aprons, to receive the web between them and carry it smoothlyfrom the inlet over and under the heated rolls to the outlet, where theelastic rolls must catch it and carry it out.

i In thedrawings, Figure 1 is a side view of the machine with thegearing that connects the various shafts removedand also thebearing-boxes on the right and showing the interior parts by dottedlines; and Fig. 2 shows the pitch-circles of the gearing by which theseveral gear-wheels engage each other to give equal surface travel tothe several moving surfaces that carry the web. Fig. 3 gives an endviewof the machine, showing also the heater, pump, and connections. Fig.4 shows a portion of the ends of the cylinders, with the guide-rolls andmetallic guide-tapes. Fig. 5 is an enlarged view of the roller-gate,paclc ing, guides, and first pair of rollers; and Fig. 6 illustrates thearrangement when the guide tapes are made to meet outside the chamber.

Ais the closed chamber, exhausted through an exhaust-pipe E, opposite towhich the covering-plate on the front of Fig. 1 closes an openingthrough which the interior can be reached to remove any pieces that failto be carried quite through.

O, O, and 0 (shown by fine dotted lines) are the cylinders, heated bysteam or hot oil through their hollow journals S, S, and S, (shown inFig. 1 in section as broken 0d,) it being understood that if heated bysteam they will be provided with the usual siphon arrangement to keepthem free from Water. Around these cylinders are carried two series ofmetallic tapes or two aprons, of cloth or woven wire. (Shown in edgeview by the lines of dashes G G in Fig. 1 and more fully in Figs. 4, 5,and 6.) These are carried over loose rollers N N N" and O O O" 0",meeting be-' tween 0 and N in a way to surely receive the web betweenthem and to carry it down under the cylinder 0, then over the next 0,and

.under the third 0" in a way to secure the longest surface contact withtheir peripheries. More such cylinders can be introduced in case theyare required to dry sensitive fiber with less heat, and the guides canbe carried around them all in succession.

It will be understood that if metallic tapes are used each series willbe made up of sev eral placed only afew inches apart and guided bygrooves N and O respectively, in the rollers N 0', Fig. 41, and 0. Thesemetallic tapes or aprons can be arranged to run over the inlet-rollersso as to receive the web outside the machine, if this web-say of thinwet paper-is not strong enough to be managed in any other way. Most webswill have body enough to allow the attendant simply to insert the endbetween the two rubber rolls R, which will deliver it to thecarrier-guides G G between the rollers N and O and start it upon itscourse. These two rolls,with rubber or other elastic surface, cannot bewell packed to move air-tight against the walls of the chamber. Wetherefore place outside of them and in rolling contact with them the twoiron rolls I I at the side of entrance and I and 1' at the exit, withthe two rubber-faced rolls R pressed between them. These upper and lowerrolls I I I I have packings P P, &c., pressing upon them from properrecesses and are practically air-tight in the side of the chamber, andthe elastic surfaces of the middle rolls R R close against them andagainst each other, allowing no air to enter between, and when any Webof paper or cloth is drawn in between them the rubber is compressedenough to allow it to pass without forcing the rolls apart. In this waywe provide for drawing through the machine a web of cloth or of paper orwarps and yarns of any length. The drying-surface is made sufficient sothat at the required speed of passing these entering wet will emergedry. A glance at Fig. 2 will show that the three cylinders are gearedtogether so as to secure equal peripheral speed, and the two iron rollsof each pair at the entrance and exit are also geared together, and anintermediate wheel connects the gears of the cylinders with those of thesmall rolls in a way to secure for them the same surface speed. Thesmall iron rolls being driven by power, the rubber rolls between themare carried at equalspeed by surface contact' If the web shrinks indrying, it may be necessary to slightly reduce the peripheral speed ofthe rolls at the exit, as may be easily done by adding one or two teethto the small gear 1. For some uses it may be necessary to provide therubber rolls with scrapers (doctors) to prevent the web winding uponthem, and we also suggest guides 10 a, which, bent back, serve also, ifneeded, as screens for the rubber rolls against excessive heat, and ifthis is not sufficient wepropose to make the small iron rolls hollow andcarry through them streams of cool water; but we hardly expect this tobe necessary and have not illustrated it in our drawings.

It may generally be sufficient to have but one roll with elastic surfacebetween the two metal rolls, and in that case those rolls should begeared to revolve in the same direction. By a different arrangement ofdriers the web might be brought out on the same side of the machine asthat by which it enters, and possibly one elastic-faced roll mightsulfice for the machine, the wet web passing in between this and onemetal roll and passing out on the other side of the same rubber roll andbetween it and the other metal roll, in that case being pressed into theelastic surface and not forcing the rolls apart or allowing air to passwith it.

For some fabrics greater heat may be properly used than can be conveyedby steam without raising the pressure unduly, and we propose for thatcondition to use some oil that has a high boiling-point and whichperhaps may be used without confining it, using a pump, if necessary, toforce it around. The use of a liquid will have the advantage that it isso in contact with the surface to be heated that heat is conducted muchmore rapidly than from a vapor like steam, and the evaporation from thewet fabric carries away heat with exceeding rapidity. The samearrangement allows the use of a liquid heated moderately and to adefinite predetermined temperature which would allow Wet leather to bedried in contact with the cylinders without injury. This arrangement forcirculating a liquid is illustrated in Fig. 3, where II is the heater, Bthe pump, and S S the pipes connecting into the hollow axles of thecylinders. This use of a liquid conveyer of heat might be of advantagein the drying-cans of the ordinary paper-machines or cloth-mills.

Some of the advantages of our drier would be secured by carrying the webon a wire apron over heating-coils, and for this the higher temperaturesecured by the liquid would be needed, heating the fabric mainly byradiation, since the thin air is so poor a conductor. This would avoidcalendering the surface of fine papers, if desired.

It is practicable to remove half the atmospheric pressure and at atemperature of some 180 Fahrenheit to boil out the water.

In the application of Ada H. Colby, administratrix, &c., for LettersPatent for process and machine for drying webs of cloth and paper, filedApril 10, 1897, Serial No. 631,506, there is shown, described, andclaimed a process similar to that carried out in our apparatus and by amachine of like principle to ours, and hence our claim herein is tocertain specific improvements peculiar to our apparatus.

We do not limit ourselves by the details of construction; but,

Having described what we consider the best form of carrying out ourinvention, we claim as follows l. A vacuum web-drier, consisting of aclosed chamber, connected internally with an exhauster and havingentrance and exit openings for the web, pairs of feed-rolls, one of eachpair with elastic surface, tightly closing these entrance and exitopenings and adapted continuously to draw in and feed out the web to bedried, and moving heated surfaces around which this web is stretched,geared to move with the same surface velocity as the ICC web, andadapted to carry it forward while evaporating the water from it,substantially as herein described.

2. A vacuum web drier, consisting of a closed chamber, having entranceand exit openings for the web, pairs of feed-rolls, one or both of eachpair with elastic surface, closing these entrance and exit openings, andadapted continuously to draw in and feed out the web to be dried, and aseries of cylinders, heated through their journals and arranged to holdthe web in contact with a considerable part of their heated surfaceswhile moving it forward, the said cylinders being connected to eachother and to the pairs of rolls by gearing and rolling contact, wherebyall have practically the same surface travel, in combination withexhausting apparatus, substantially as herein set forth.

3. In a vacuum web-drier, in combination with the exhausted chamber, andwith the moving heated surfaces within it, two series of endlessmetallic tapes, carrying-rolls having grooves by which the tapes areguided, the said tapes stretched around and traveling in the path bywhich the web is to move, each series of tapes made up of several suchtapes and spaced near each other, and the two series adapted to receivethe said web between them, and hold it to its course, while sufficientlyexposing it to permit free evaporation, substantially as described.

4. In a vacuum web-drier, in combination with the closed chamber and itsexhauster, a series of rolls between which the web to be dried may enterthe chamber, and a similar series between which it may pass out, theouter two rolls of each series having a hard smooth surface, packedagainst the walls of the chamber, and the middle roll or rolls, be-' ingof elastic surface, in rolling contact with the outer two rolls, andadapted to close upon the web as it rolls in and out and prevent the airfrom entering, substantially as set forth.

5. In a vacuum web-drier, the combination of a closed chamber, connectedinternally with an exhauster and having entrance and exit openings forthe web, pairs of'feed-rolls, one

of each pair with elastic surface, tightly closing these openings, andadapted continuously to draw in and feed out the web to be dried, andmoving surfaces heated from within by a liquid (such as oil) which willnot vaporize at the heating temperature required, the said movingsurfaces being geared to move with the same surface velocity as the web,and adapted to carry this web forward, while evaporating its moisture,and appliances for heating and circulating the heating liquid, wherebythe exact temperature best suited for drying any substance in vacuo ismaintained in the said moving surfaces in contact with the web of thissubstance, substantially as described.

6. In apparatus for drying webs of cloth or paper, the combination of aclosed chamber, connected internally with an exhauster and havingentrance and exit openings for the web, pairs of feed-rolls, one of eachpair with elastic surface, tightly closing these openings, and adaptedcontinuously to draw in and feed out the web to be dried, and rotaryhollow cylinders, over the surface of which such web passes, geared tomove with the same surface speed as the web and adapted to carry the webforward, while evaporating its moisture, a liquid conveyer of heat, ofwhich the boiling-point is higher than the required temperature of saidcylinders, introduced into the cylinders through their journals, andapparatus for heating such liquid and circulating it through saidcylinders, whereby the heat of their surfaces in contact with the web tobe dried is maintained at the predetermined temperature best suited forcooperating with the exhaust in treating the material of this web,substantially as specified.

In testimony whereof we have signed our names to this specification, inthe presence of two subscribing witnesses, on this 5th day of February,A. D. 1897.

HOWARD PARKER. HENRY FAIRBANKS. Witnesses:

PAUL S. CARTER, C. II. HORTON.

